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Neuropsychology focuses on (a) basic research, (b) the integration of basic and applied research, and (c) improved practice in the field of neuropsychology. The primary function of Neuropsychology is to publish original, empirical research on the relation



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Perceptual and response-dependent profiles of attention in children with ADHD.

2017-04-03

Objective: Attention-deficit hyperactivity disorder (ADHD) is a complex developmental neuropsychiatric disorder, characterized by inattentiveness, impulsivity, and hyperactivity. Recent literature suggests a potential core deficit underlying these behaviors may involve inefficient processing when contextual stimulation is low. In order to specify this inefficiency, the aim of the present study was to disentangle perceptual and response-based deficits of attention by supplementing classic reaction time (RT) measures with an accuracy-only test. Moreover, it was explored whether ADHD symptom severity was systematically related to perceptual and response-based processes. Method: We applied an RT-independent paradigm (Bundesen, 1990) and a sustained attention task (Dockree et al., 2006) to test visual attention in 24 recently diagnosed, medication-naïve children with ADHD, 14 clinical controls with pervasive developmental disorder, and 57 healthy controls. Outcome measures included perceptual processing speed, capacity of visual short-term memory, and errors of commission and omission. Results: Children with ADHD processed information abnormally slow (d = 0.92), and performed poorly on RT variability and response stability (d′s ranging from 0.60 to 1.08). In the ADHD group only, slowed visual processing speed was significantly related to response lapses (omission errors). This correlation was not explained by behavioral ratings of ADHD severity. Conclusions: Based on combined assessment of perceptual and response-dependent variables of attention, the present study demonstrates a specific cognitive profile in children with ADHD. This profile distinguishes the disorder at a basic level of attentional functioning, and may define subgroups of children with ADHD in a way that is more sensitive than clinical rating scales. (PsycINFO Database Record (c) 2017 APA, all rights reserved)(image)



Facial emotion recognition, face scan paths, and face perception in children with neurofibromatosis type 1.

2017-03-20

Objective: This study aimed to investigate face scan paths and face perception abilities in children with Neurofibromatosis Type 1 (NF1) and how these might relate to emotion recognition abilities in this population. Method: The authors investigated facial emotion recognition, face scan paths, and face perception in 29 children with NF1 compared to 29 chronological age-matched typically developing controls. Correlations between facial emotion recognition, face scan paths, and face perception in children with NF1 were examined. Results: Children with NF1 displayed significantly poorer recognition of fearful expressions compared to controls, as well as a nonsignificant trend toward poorer recognition of anger. Although there was no significant difference between groups in time spent viewing individual core facial features (eyes, nose, mouth, and nonfeature regions), children with NF1 spent significantly less time than controls viewing the face as a whole. Children with NF1 also displayed significantly poorer face perception abilities than typically developing controls. Facial emotion recognition deficits were not significantly associated with aberrant face scan paths or face perception abilities in the NF1 group. Conclusions: These results suggest that impairments in the perception, identification, and interpretation of information from faces are important aspects of the social–cognitive phenotype of NF1. (PsycINFO Database Record (c) 2017 APA, all rights reserved)(image)



A specific implicit sequence learning deficit as an underlying cause of dyslexia? Investigating the role of attention in implicit learning tasks.

2017-02-02

Objective: Recently, a general implicit sequence learning deficit was proposed as an underlying cause of dyslexia. This new hypothesis was investigated in the present study by including a number of methodological improvements, for example, the inclusion of appropriate control conditions. The second goal of the study was to explore the role of attentional functioning in implicit and explicit learning tasks. Method: In a 2 × 2 within-subjects design 4 tasks were administered in 30 dyslexic and 38 control children: an implicit and explicit serial reaction time (RT) task and an implicit and explicit contextual cueing task. Attentional functioning was also administered. The entire learning curves of all tasks were analyzed using latent growth curve modeling in order to compare performances between groups and to examine the role of attentional functioning on the learning curves. Results: The amount of implicit learning was similar for both groups. However, the dyslexic group showed slower RTs throughout the entire task. This group difference reduced and became nonsignificant after controlling for attentional functioning. Both implicit learning tasks, but none of the explicit learning tasks, were significantly affected by attentional functioning. Conclusions: Dyslexic children do not suffer from a specific implicit sequence learning deficit. The slower RTs of the dyslexic children throughout the entire implicit sequence learning process are caused by their comorbid attention problems and overall slowness. A key finding of the present study is that, in contrast to what was assumed for a long time, implicit learning relies on attentional resources, perhaps even more than explicit learning does. (PsycINFO Database Record (c) 2017 APA, all rights reserved)(image)



"Understanding the role of speech production in reading: Evidence for a print-to-speech neural network using graphical analysis": Correction to Cummine et al. (2016).

2017-04-27

Reports an error in "Understanding the role of speech production in reading: Evidence for a print-to-speech neural network using graphical analysis" by Jacqueline Cummine, Ivor Cribben, Connie Luu, Esther Kim, Reyhaneh Bahktiari, George Georgiou and Carol A. Boliek (Neuropsychology, 2016[May], Vol 30[4], 385-397). In the article, the fifth author’s name [Bakhtiari] was misspelled. The online version of this article has been corrected. (The following abstract of the original article appeared in record 2015-49069-001.) Objective: The neural circuitry associated with language processing is complex and dynamic. Graphical models are useful for studying complex neural networks as this method provides information about unique connectivity between regions within the context of the entire network of interest. Here, the authors explored the neural networks during covert reading to determine the role of feedforward and feedback loops in covert speech production. Method: Brain activity of skilled adult readers was assessed in real word and pseudoword reading tasks with functional MRI (fMRI). Results: The authors provide evidence for activity coherence in the feedforward system (inferior frontal gyrus—supplementary motor area) during real word reading and in the feedback system (supramarginal gyrus—precentral gyrus) during pseudoword reading. Graphical models provided evidence of an extensive, highly connected, neural network when individuals read real words that relied on coordination of the feedforward system. In contrast, when individuals read pseudowords the authors found a limited/restricted network that relied on coordination of the feedback system. Conclusion: Together, these results underscore the importance of considering multiple pathways and articulatory loops during language tasks and provide evidence for a print-to-speech neural network. (PsycINFO Database Record (c) 2017 APA, all rights reserved)(image)



Attention-deficit/hyperactivity disorder and phonological working memory: Methodological variability affects clinical and experimental performance metrics.

2017-03-09

Objective: Despite promising findings in extant research that suggest impaired working memory (WM) serves as a central neurocognitive deficit or candidate endophenotype of attention-deficit/hyperactivity disorder (ADHD), findings from translational research have been relatively underwhelming. This study aimed to explicate previous equivocal findings by systematically examining the effect of methodological variability on WM performance estimates across experimental and clinical WM measures. Method: Age-matched boys (ages 8–12 years) with (n = 20) and without (n = 20) ADHD completed 1 experimental (phonological) and 2 clinical (digit span, letter–number sequencing) WM measures. Results: The use of partial scoring procedures, administration of greater trial numbers, and high central executive demands yielded moderate-to-large between-groups effect sizes. Moreover, the combination of these best-case procedures, compared to worst-case procedures (i.e., absolute scoring, administration of few trials, use of discontinue rules, and low central executive demands), resulted in a 12.5% increase in correct group classification. Conclusion: Collectively, these findings explain inconsistent ADHD-related WM deficits in previous reports, and highlight the need for revised clinical measures that utilize best-case procedures. (PsycINFO Database Record (c) 2017 APA, all rights reserved)(image)



Altered resting-state EEG complexity in children with Tourette syndrome: A preliminary study.

2017-03-20

Objective: Tourette syndrome is a developmental neuropsychiatric disorder in children, and abnormal corticobasal ganglion connectivity is implied for the pathophysiology. Multiscale entropy, an entropy-based method to measure dynamic complexity at multiple temporal scales, is helpful to disclose the information of brain connectivity. This preliminary study investigated the complexity of resting-state electroencephalogram signals using multiscale entropy in children with Tourette syndrome. Method: Resting-state electroencephalographic (EEG) signals were analyzed by sample entropy and multiscale entropy methods in 10 children with Tourette syndrome and 10 healthy gender- and age-matched controls. Results: Except for the Fp2 channel, the complexity index values in all channels were reduced in children with Tourette syndrome compared with those in normal controls. A statistically significant reduction in EEG complexity was found in the bilateral central, parietal, occipital, and left temporal regions, indicating disturbed brain connectivity in Tourette syndrome. Although there was no difference of complexity in the higher frequency spectra, there was a statistically significant difference of complexity in lower frequency in F3 channel, pointing to the importance of examining a range of time scales in exploring EEG signals. Conclusions: Our preliminary study demonstrated that EEG complexity was significantly lower in children with Tourette syndrome than in normal controls. This difference may serve as a marker of disturbed brain connectivity in such individuals and suggests that further clinical studies are warranted. (PsycINFO Database Record (c) 2017 APA, all rights reserved)(image)



Sustained attention in the face of distractors: A study of children with Rett syndrome.

2017-04-06

Objective: The object of the present study is to advance our understanding of the cognitive profile of Rett syndrome (RTT), an X-linked neurodevelopmental disorder caused by mutations in the MECP2 gene. We focus on sustained attention, which plays a critical role in driving cognitive growth, and use an innovative, gaze-based task that minimizes demands on the limited verbal and motor abilities associated with RTT. Method: The task required the ability to sustain attention on a visual target (a butterfly) while inhibiting a prepotent response to look to moving distractors (trees and clouds) presented in the peripheral visual field. The sample included children with RTT (N = 32) and their typically developing (TD) counterparts (N = 32), aged 2–12 years. Results: Our findings revealed that children with RTT had more difficulty sustaining attention (with the TD group averaging 60% looking at the butterfly vs. only 25% for the RTT group). Furthermore, RTT was associated with difficulties in 3 fundamental factors influencing sustained attention: engagement, distractibility, and reengagement. The RTT group was slower to engage, more distractible, and slower to reengage. Conclusion: Our findings identify a fundamental disruption to sustained attention in RTT, determine factors related to this impairment, and pinpoint cognitive areas that could serve as markers for evaluating the effectiveness of pharmacological and behavioral interventions. (PsycINFO Database Record (c) 2017 APA, all rights reserved)(image)



Cognitive control and associated neural correlates in adults with spina bifida myelomeningocele.

2017-02-16

Objective: Accelerated aging can occur in adult survivors of neurodevelopmental disorders, but has been narrowly studied in spina bifida myelomeningocele (SBM). Since discrete aspects of cognitive control and related neural network macrostructure deteriorate in normal aging, the specificity and trajectory of cognition and neuropathology incurred across adulthood in SBM were examined. Method: Adults (N = 120) with and without SBM completed working memory span and manipulation tasks, and an inhibitory control task. A subset (n = 53) underwent structural MRI. Effects of group, age, and their interaction on performance and select gray matter volumes were examined. Results: Adults with SBM had significantly poorer working memory accuracy and overall inhibitory control performance than typical peers. Age negatively predicted inhibitory control. Group × Age significantly interacted on span accuracy; advanced age related to diminished performance in typical adults, but not in adults with SBM. SBM related to disproportionately enlarged cortical and putamen and reduced hippocampus volumes. Group × Age significantly interacted on cortical, but not subcortical gray matter volumes. Dorsolateral prefrontal, hippocampus, and putamen volumes negatively correlated with cognitive performance. Conclusions: Supporting previous literature, current findings elucidated a profile of executive impairment in SBM that was maintained in a parallel maturational trajectory to typical aging. Accelerated aging in cognitive control or subcortical gray matter was not supported in SBM. However, reductions in anterior and posterior cortical regions were exacerbated in older adults with SBM compared with typical peers. Overall results supported persistent anomalous neurodevelopmental maturation across the life span in SBM that related to diminished cognitive control. (PsycINFO Database Record (c) 2017 APA, all rights reserved)(image)



Attentional impairments in Huntington’s disease: A specific deficit for the executive conflict.

2017-02-27

Objective: Huntington’s disease (HD) is characterized by motor and cognitive impairments including memory, executive, and attentional functions. However, because earlier studies relied on multidetermined attentional tasks, uncertainty still abounds regarding the differential deficit across attentional subcomponents. Likewise, the evolution of these deficits during the successive stages of HD remains unclear. The present study simultaneously explored 3 distinct networks of attention (alerting, orienting, executive conflict) in preclinical and clinical HD. Method: Thirty-eight HD patients (18 preclinical) and 38 matched healthy controls completed the attention network test, an integrated and theoretically grounded task assessing the integrity of 3 attentional networks. Results: Preclinical HD was not characterized by any attentional deficit compared to controls. Conversely, clinical HD was associated with a differential deficit across the 3 attentional networks under investigation, showing preserved performance for alerting and orienting networks but massive and specific impairment for the executive conflict network. This indexes an impaired use of executive control to resolve the conflict between task-relevant stimuli and interfering task-irrelevant ones. Conclusion: Clinical HD does not lead to a global attentional deficit but rather to a specific impairment for the executive control of attention. Moreover, the absence of attentional deficits in preclinical HD suggests that these deficits are absent at the initial stages of the disease. In view of their impact on everyday life, attentional deficits should be considered in clinical contexts. Therapeutic programs improving the executive control of attention by neuropsychology and neuromodulation should be promoted. (PsycINFO Database Record (c) 2017 APA, all rights reserved)(image)



Cognitive profile and mental health in adult phenylketonuria: A PKU-COBESO study.

2017-03-20

Objective: Despite early dietary treatment phenylketonuria patients have lower IQ and poorer executive functions compared to healthy controls. Cognitive problems in phenylketonuria have often been associated with phenylalanine levels. The present study examined the cognitive profile and mental health in adult phenylketonuria, in relation to phenylalanine levels and tetrahydrobiopterin treatment. Method: Fifty-seven early treated adult patients with phenylketonuria and 57 healthy matched controls (18–40 years) performed IQ subtests and executive function tests from the Amsterdam Neuropsychological Tasks. They also completed the Adult Self-Report on mental health problems. Analyses of variance were performed to examine group differences. Results: Patients with phenylketonuria had normal IQs although lower than controls. They performed poorer on working memory, inhibitory control, and sustained attention tasks. Patients reported Depressive and Avoidant Personality problems more frequently. Specifically, patients with childhood and lifetime phenylalanine ≥360 μmol/L had poorer cognitive and mental health outcomes than controls. In a subset of patients, comparisons between patients on and off tetrahydrobiopterin showed that nontetrahydrobiopterin users (matched for childhood, pretreatment phenylalanine) were slower (on number of tasks) and reported more mental health problems. Conclusions: Adult patients had lower IQ and poorer executive functions than controls, resembling problems observed in younger patients with phenylketonuria, as well as more internalizing problems. Group differences and phenylalanine-outcome associations were smaller than those observed in younger populations. A subset of nontetrahydrobiopterin users, matched for childhood phenylalanine level, had a poorer outcome on some tests than tetrahydrobiopterin users, which might indicate an impact of tetrahydrobiopterin treatment beyond lowering phenylalanine. However, clinical relevance needs further investigation. (PsycINFO Database Record (c) 2017 APA, all rights reserved)(image)



Specificity of executive functioning and processing speed problems in common psychopathology.

2017-01-16

Objective: Interest continues in neuropsychological measures as cross-disorder intermediate phenotypes in understanding psychopathology. A central question concerns their specificity versus generalizability to particular forms of psychopathology, particularly for executive functioning (EF) and response speed. Three conceptual models examining these relationships were tested to clarify this picture at different levels in the diagnostic hierarchy. Method: Participants (total n = 641, age 18–60) yielded complete structured diagnostic interviews and a neuropsychological test battery comprising measures of executive function, processing speed, and IQ. Repeated measures multivariate analysis of variance, linear regression, and structural equation modeling (SEM) were used to test (a) a specificity model, which proposes that individual disorders are associated with component EF processes and speed; (b) a severity model, which proposes that the total number of comorbid disorders explain poor EF and/or slow speed; and (c) a higher-order dimensional model, which proposes that internalizing versus externalizing disorders are differentially related to EF or speed. Results: EF effects were best explained by a specificity model, with distinct aspects of EF related to attention deficit hyperactivity disorder versus antisocial substance use disorders. Speed, on the other hand, emerged as a general indicator of externalizing psychopathology in the dimensional model, as well as overall severity of psychopathology in the severity model. Conclusions: Granular approaches are likely to be most productive for linking EF to psychopathology, whereas response speed has underused potential as an endophenotype for psychopathology liability. Results are discussed in terms of an integrated conceptualization of neuropsychological processes and putative neural systems involved in general and specific aspects of psychopathology. (PsycINFO Database Record (c) 2017 APA, all rights reserved)(image)



Is longer treatment better? A comparison study of 3 versus 6 months cognitive remediation in schizophrenia.

2017-02-02

Objective: Despite its extensive use for treating cognitive deficits in schizophrenia, computer-assisted cognitive remediation (CACR) currently lacks a standardized protocol. Duration is an important feature to be defined, as it may contribute to heterogeneous outcome. This study compares 2 treatment durations, 3 versus 6 months, to analyze their effects on both cognition and daily functioning. Method: Fifty-seven outpatients with schizophrenia received 3 months of CACR and 41 received 6 months of CACR. All patients were assessed at baseline and after 3 and 6 months with the Brief Assessment for Cognition in Schizophrenia and with the Quality of Life Scale (QLS). Results: Repeated measures ANOVA showed significant improvements in all cognitive domains after 3 months. A significant effect of treatment duration was observed only for executive functions, with significantly higher scores among patients treated for 6 months. Significant improvements in QLS were also observed after 6 months in both groups, with a significant time by treatment interaction for QLS Total Score. Conclusions: Results confirm the efficacy of 3-months CACR in terms of both cognitive and functional improvements, suggesting that an extended intervention may lead to further benefits in executive functions and daily functioning. (PsycINFO Database Record (c) 2017 APA, all rights reserved)(image)